Method of thawing materials



Sept; 21, 1948. J. w. FORSYTHE ETAL 2,449,932

METHOD OF THAWING MATERIALS Filed Jan. 24, 1945 2 Sheets-Slaget 1 FIE 1.

" g Y [am/e01 5/407259 4m INVENTDRSI e/r Jib/723% Sept. 21, 1948. u. w. FORSYTHE ETAL I 2 METHOD OF THAWING MATERIALS Filed Jan. 24, 1945 I 2 Shets-Sheet 2 Patented Sept. 2i, 1948 auassa METHOD or THAWING MATERIALS John W. Forsythe, deceased, late of Wilkinsburg,

Pa., by MaryAllce Forsythe, executrix, Wilkinsburg, Pa., and Edward J. Smotzer, Pittsburgh, Pa., asslgnors' to Carnegie-Illinois Steel Corporation. a corporation of New Jersey Application January 24, 1945, Serial No. 574,436

1 Claim.

Thisinvention relates to a method of heating materials; more particularly it relates to a method of thawing materials in containers such as cars and the like.

One of the objects of the invention is the provision of a method for thawing materials in containers to allow their discharge therefrom. This and further objects of the invention will become apparent as the description proceeds.

Materials such as ore, limestone, coke, and coal, as well as other similar materials produced or occurring in broken or granular forinare transported most economically in open railroad cars and the like from which they are discharged at the point of use or storage, either from bottom openings in the camp! by means of car dumpers which invert the entire car. Such discharge of materials is rendered diflicult in cold weather by reason of freezing of the materials in the cars in transit or while standing in the yard due to rain, snow, and ice falling on them. The problem of discharge of the cars is most serious where the material is shipped from lake ports where it is subjected to the damp atmosphere prevailing in such localities. I

Various expedients have been tried in the past to thaw and loosen the frozen materials in the cars sufficiently to permit their ready discharge therefrom. Such methods have included the building of wood fires under the cars, the holding of gas jets against the sides of the cars in various places, and the use of steam baths to which parts of the car or the whole car have been subjected. The first two methods are obviously crude and hit-or-miss. Besides requiring a considerable amount of time, they are further open to the very serious objection that they subject portions of the car to 'sufliciently high temperatures to damage the paint thereon, and even to buckle and otherwise seriously weaken the sides and frames of the cars. Steam baths are also slow and do not in the main impart sufficient heat to the car and its contents to insure thorough thawing of the material. Furthermore, because of the moisture contained in the steam, icing of the apparatus at the thawing station, particularly in very cold weather, inevitably results.

By use of the method of the present invention, the difficulties above outlined attendant upon the use of prior-thawing methods are overcome. Briefly, the invention provides means for completely enclosing one or more materialc'arryin devices, such as railroad cars, and for subjecting such cars in the initial portion of the heating cycle to a moderately high temperature.

2. which may be, for example, on the order of 750 F., following which the heat is cut back and the car and its contents allowed to soak in the latter part of the cycle at a lower temperature, which may be, for example, on the order of 250 F. Upon completion of the thawing cycle, the container, which may be, for example, a railroad car, is transferred to the discharge station, which may be a car dumper, whereupon additional cars are charged into the thawing chamber or enclosure and the thawing cycle repeated, In the preferred embodiment of the apparatus described in the following disclosure for purposes of illustration, the operation of the heating means and of various protective devices are made automatically responsive to the travel of the thawing chamber closure means whereby a minimum of manual control is required of the operator.

The invention will be more fully understood by reference to the accompanying drawings, in which:

Figure l is a side elevation, partially in section, of the thawing chamber; and

Figure 2 is a view in cross section of the thawing chamber taken along the line IL-II of Figure 1. Y

The thawing building shown in Figures 1 and 2, which may be of brick or'other heat-resistant material, is designated generally by the reference character I. Building I consists of a foundation 2, the upper surface of which lies at ground level. The buildin is provided with ends 3 closing the upper portions thereof, and with two doors I and 5, door 4 to the left of Figure 1 being sometimes referred to as door #1, and door 5 to the right in Figure 1 being sometimes referred to as door #2. The doors are each provided with a hoisting mechanism, Whereby they are lifted suillciently to allow railroad cars to enter and leave the chamber, the hoisting mechanism for door 4 comprising top sheaves 6 and lowering and hoisting drum 8, the corresponding parts of a similar hoisting mechanism for door 5 being designated I and 9, respectively.

The lower portion of the thawing building is completed by side walls l0 and H and by ceiling I2 which forms a floor for the upper portion of the structure. The upper portion of the structure I, which houses the gas heating and circulating means subsequently to be described, is provided with sides l3 and roof l5, as shown in Figures 1 and 2.

The lower or thawing chamber of the structure is made wide enough, in the particular embodiment shown, to receive a standard railroad car II, on tracks i8, and a narrow gauge electric pusher locomotive IS, on tracks ll, side by side. Locomotive i9 is provided with a retractable side pusher arm (not shown) which may be advanced to engage the rear of the car to be moved. Such design has been found to lend flexibility to the layout, since the narrow gauge locomotive is not impeded in its travel by the railroad cars, but may proceed to pick up as many or as few cars as are desired. In addition, the space above the narrow gauge track is useful as a walkway when the loco-,- motive is removed and the thawing apparatus is not in use. It is to be understood, however, that other means for moving the cars into and through the thawing device may b"employed if desired. Locomotive l9, which is of less height than the cars i1, runs under overhanging portion 20 of the chamber, which forms a portion of th return air flue, which will be subsequently described.

The heating of the air by which thawing of the material is accomplished is performed by two similar heating devices 2i, located on the floor of the upper portion of the structure. The lefthand heating device 21 in Figure 1 will sometimes be referred to as unit No. 1, and the righthand device will be referred to as unit No. 2. Each such heating device 2! comprises a combustion chamber 22, into which is directed the flame from oil burner 23. Such burner is provided, as shown in Figures 1 and 4, with an oil supply pipe 24, a. steam pipe 2,5 for supplying steam for atomizing the oil. and a combustion air blower 28 driven by motor 28 for delivering air to the burner through delivery pipe 2!". The products of combustion travel longitudinally of combustion chamber 22 upwardly through opening 21 in the rear thereof into mixing chamber 28 where they are intimately admixed with recirculated air from the lower thawing chamber of the apparatus. Such recirculated air travels upwardly from the thawing chamber through uptakes or lines ll (see Figure 2), laterally into passage 30, upwardly and then laterally through passages II and then upwardly through passages from which it emerges into the mixing chamber.

Circulating air fan 33, driven by motor 34, draws the mixture of recirculated air and products of combustion from mixing chamber 28 into the housing '35 in which the fan is located, and

then discharges it under pressure into discharge duct 36. Each fan 33 is provided with a damper I! in the discharge pipe thereof, whereby, in the event of failure of one heating device II or of any of its attendant parts it may be closed off from duct 36 and the entire heating burden borne by the other heating device.

Discharge ducts 38 are connected to ducts 38,

.which extend longitudinally of the ceiling of the thawing device, as shown in Figures 1 and 2. Vertical discharge pipes 38 and 40, pipes 39 being 'on the right-hand side of Figure 2 and pipe 40 being on the left-hand side, are connected to longitudinal ducts 38 at substantially uniform spaced points. The thawing chamber shown is designed to take two standard ninety-ton ore cars coupled end to end. It is for this reason that there is a slightly greater space between theadjacent vertical pipes at the longitudinal center of the chamber, that is, the position of the coupling between'cars, than between those elsewhere. Pipes 39, which run only to the top of overhang 20, are each provided with an upper nozzle Al and a lower nozzle 42, discharging the heated air to the contents of the car, and down the side of the car. respectively. Pipes 4! are provided with upper nozzles 43, which discharge the heated air against the other side of the car.

Each pipe 40 is also provided with lower nozzles.

alternate pipes having lower nozzles 46 which discharge the heated ga horizontally under the car, and the other pipes 40 havin lower nozzles I M which discharge the gas upwardly at an angle against the side of the car. Each nozzle is provided with its own independent damper I, of which one is shown in Figure 2 in conjunction with .nozzle til, to control the delivery or gas therefrom, and each nozzle is preferably made of a fish tail shape to provide a heated gas iet having a broad coverage over the urface of the car and its contents.

When using the particular apparatus above described, in the thawing of two ninety-ton ore cars at one time, it has been found that, with heating devices 2! with a rated capacity of 10 million B. t. u. per hour each, a ten-minute preliminary heating period of 500-700 F., followed a cut-back to soaking at 200-250 F. for from 5 to 20 minutes is sufllcient to thaw most if not all cars encountered during ordinary winter weather, to an extent sumcient to allow their being emptied in a satisfactory manner by a car dumper which inverts the cars. It i usually necessary to thaw the material to a depth of only about one inch from the car walls and bottom to accomplish the desired freeing of the material from the car. Under exceptionally severe freezing conditions it may be necessary to increase either the length of the preliminary high temperature heating period or the soaking period, or both, and for light freezing conditions either or both heating periods may be shortened. Within the scope of the method of the present invention there may be employed, therefore, a preliminary heating at from 500 to 750 F. for from 5 to 15 minutes, and a subsequent heat-- ing at from 200 to 250 F. for from 5 to 20 minutes.

Preferably an automatic control system is provided by which the thawing temperatures are maintained at the prescribed values for the prescribed periods. The details of this system are not described for the reason that the are fully disclosed and claimed in our co-pending application Serial No. 609,639, filed August 8, 1945, as a division of the present application.

Use of the method of the present invention has been found to overcome a serious bottleneck in the handling of ore, limestone, and coke in the winter time. In addition to the speed and certainty with which such materials may now be dumped after the thawing by such device, it has been found that no injury results to the cars by reason of such heating. The metal work, paint, rubber air hoses, and rubber hose gaskets show no deterioration resulting from such treatment, which is in marked contrast to the damage caused by the previous use of wood fires or gas jets in thawing the cars.

Whereas a particular method of thawing has been described for purposes of illustration, it is obvious that numerous variations within the teaching of the invention are obvious to one skilled in the art. The scope of the invention is therefore defined by the appended claim.

We claim:

A method of thawing frozen materials in railroad cars comprising subjecting a car situated in c osed thawing chamber to a plurality of 2,449,989 5 6 blasts 01' a gaseous blend of air and product of REFERENCES ITED combustion temperature to The following references are of record in the continuously removing the blast gases from the me of this patent; chamber, blending a portion of the gases thus removed 'with additional air and products of 5 UNITED STATES. PATENTS combustion, continuously recirculating the result- Number Name t in: blend of gases to the blast; at this temper- 903, 35 Uphus r, a] 1 1908 ature tor-'5 to 18 minutes; and thereafter sub- 992,295 Tlemann May 1 1911 .10 the 1'30 a plurality o! similarly 00n- 1,179,953 Newhall et a1 Apr. 18, 1916 stituted blasts at a temperature of 200 to 250' 10 1,277,996 Newhall Sept. 9, 1918 1'. for a period of 5 to 20 minutes. 1,300,701 Crosby et a1 Apr. 15, 1919 MARY I E F0R8YTHE- 1,443,929 Weigert Jan. 23, 1923 l'zecutris: of the Estate of John W. Forsy e. 1,747,919 Steins Feb. 18, 1930 Deceased. 1,798,141 Cowan Mar. 10, 1931 EDWARD J. SMOTZER. 15 

